Reaction product of a polycarboxylic acid and oxypropylated triricinolein



United States Patent M REACTION PRODUCT OF A POLYCARBOXYLIC ACID AND OXYPROPYLATED TRIRICINOLEIN Alvin Howard Smith, Kirkwood, Mo., assignor'to Petrolite Corporation, a corporation of Delaware No Drawing. Application April 10, 1952, Serial No. 281,648

12 Claims. (Cl. 260-4043) The present invention is concerned with certain new chemical products, compounds, or compositions which have useful applications in various arts. It includes methods or procedures for manufacturing said new chemical products, compound, or compositions, as well as the products, compounds, or compositions themselves.

Complementary to the above aspect of the invention herein disclosed in my companion invention concerned with the use of these particular chemical compounds, or products, as demulsifying agents in processes or procedures particularly adapted for preventing, breaking, or resolving emulsions of the Water-in-oil type, and particularly petroleum emulsions. See my co-pending application, Serial No. 281,647, filed April 10, 1952.

The present invention is concerned with certain hydrophile synthetic products; said hydrophile synthetic products being acidic fractional esters obtained by reaction between (A) A polycarboxy acid, and

(B) Excessively oxypropylated triricinolein which is cgmmercially available as castor oil, with the proviso t at (1) There be introduced at least moles and preferably not over 50 moles, and generally not over 40 moles, of propylene oxide per ricinoleyl radical, and that (2) There be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical.

It is understood that castor oil which is the commercial form of triricinolein contains small amounts of other fatty acid radicals insofar that commercial castor oil is apt to comprise from slightly over 85% to slightly over 90% ester of ricinoleic acid. However, the reference to the ricinoleic or the ricinoleyl radical means the mixed fatty acids present in castor oil for the reason that for all practical purposes they are 85 %-90% or more triricinolein. purified or separated so as to yield pure ricinoleic acid which could be esterfiied to produce a glyceride containing 90% or more of triricinolein. Such procedures would be expensive and there is no justification for them. Thus, for the present purpose castor oil and triricinolein are considered synonomous.

The oxyalkylation of castor oil appears to be more complicated than indicated by initial examination. Originally it was believed that the oxyalkylation and particularly the oxyethylation of castor oil, since it yielded a water-soluble product in the case of ethylene oxide, involved the hydroxyl group of the ricinoleyl radical. Subsequently it was found, as is well known, that non- ,hydroxylated glycerides, for instance, olein, also can be solubilized by the use of ethylene oxide and it is now believed that the reaction takes place under such circumstances at the ester linkage. It is believed, also, that in the oxyalkylation of castor oil the ester linkage seems to be more susceptible to oxyalkylation than the secondary alcohol group. However, depending on circumstances there may be some oxypropylation taking place at the secondary alcoholic linkage.

The oxyethylation of castor oil is well known, particularly with ethylene oxide, in order to obtain a watersoluble or water-emulsifiable product. All that is required is a comparatively low ratio of ethylene oxide per ricinoleyl radical, for instance, about 3 or 4 moles per ricinoleyl radical. Sometimes mixtures of both propylene oxide and ethylene oxide have been used to obtain a product which was still water-soluble and water-emulsifiable.

Needless to say, castor oil can be In some instances castor oil has 2,695,909 Patented Nov. 30, 1954 been reacted with a comparatively low ratio of propylene oxide, for instance, several moles per ricinoleyl radical.

As far as -I am aware no previous eifort has been made to react castor oil with the excessive amount of propylene oxide which I introduce to give a decided 'hydrophobe effect. For instance, one mole of castor oil has been treated with 40 moles of propylene oxide. I have found that this amount is insufiicient for my purpose. Compounds or demulsifying agents derived from castor oil which has been treated with as little as 40 moles of propylene oxide per mole of triricinolein are not suitable. Indeed, my lower limit is approximately 50% higher and the upper limit is approximately three times this amount, i. e., 60 to moles of propylene oxide per mole of triricinolein or castor oil.

Exploring what has been said just previously, and in order to point out the nature of the oxypropylationproduct which I employ as an intermediate it may be Well to re-examine the difference in action as far as water-solubility goes between ethylene oxide and propylene oxide. If a water-soluble substance, such as water itself, is treated with ethylene oxide the resultant or mixture of compounds so obtained continues to be water-soluble to a high molecular weight range, for instance, 2,000. If, on the other hands, propylene oxide is used instead of ethylene oxide, then and in that event approximately 12 moles or more of propylene oxide are introduced per hydrophile unit and water-insolubility results. For example, compare the water-insolubility of polypropylene glycol of a molecular weight of approximately 600 or 650, with polyethyleneglycol having twice this molecular weight. In other words, a molecular weight of 600 or thereabouts means the introduction of about 10, 11 or 12 moles of propylene oxide per mole of water, so as to obtain a water-insoluble and substantially oil-soluble polyglycol.

If one momentarily considers triricinolein interms of ricinoleic acid what has been said previously may be presented in simpler language. Ricinoleic acid is, of course, water-insoluble. If reacted with 10, 11, 12 or 13 moles of propylene oxide the resultant fractional ester is essentially more insoluble than the original ricinoleic acid if such terminology can be employed for the instant description. In other words, the introduction of 10, 11, 12 or 13 moles of propylene oxide are suflicient to render a Water-soluble material (even water itself) water-insoluble and oil-soluble.

As previously pointed out, this appears to be the previously used upper limit as far as I am aware in the oxypropylation of castor oil, i. e., roughly 40 moles of propylene oxide per mole of castor oil. In order to obtain a suitable raw material here the amount used must .011, my minimum is 50% more, 1. e., 60 moles, or as much as 120 moles. In other words, I have employed an amount of propylene oxide to produce excessive oxypropylation, .i. e., a minimum of 20 moles per mole of ricinoleic acid in order to produce an excessive hydrophobe effect per ricinoleyl radical in the manner previously referred to, i. e., a hydrophobe effect which is at least 50% more than would be required to convert water into a water-insoluble material.

I Wish to emphasize that, as far as I am aware, such excessive oxypropylation of castor oil has not been recorded previously. It is this excessive oxypropylation in combination with the polycarboxy reactant which gives .a. new product which is particularly valuable for various cation but also is illustrated by utility in other fields, such as clarification of dry cleaner solvent as pointed out subsequently.

As pointed out previously it is impossible to indicate exactly the products obtained by the oxypropylation of castor oil in light of the fact that the reactions are not clearly understood and also in light of two other facts which are brought out in Part 2, subsequently;

(a) That one does not obtain a single compound in oxyalkylation and particularly oxypropylation but one obtains a cogeneric mixture, and

(b) It has long been recognized that certain unpreventable side reactions take place.

Having obtained the oxypropylated castor oil previously described and hereinafter illustrated in detail, the next step is estcrification involving a polycarboxy acid and preferably a dicarboxy acid or reactant in a molal ratio to insure that the final product is an acidic fractional ester obtained by the use of one mole of the polycarboxy reactant for each hydroxyl radical.

Although the herein described products have a number of industrial applications, they are of particular value for resolving petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. This specific application is described and claimed in my copending application, Serial No. 281,647, filed April 10, 1952.

The new products are useful as wetting, detergent and leveling agents in the laundry, textile and dyeing industries; as wetting agents and detergents in the acid washing of building stone and brick; as wetting agents and Spreaders in the application of asphalt in road building and the like; as a flotation reagent in the flotation separation of various aqueous suspensions containing negatively charged particles, such as sewage, coal washing waste water, and various trade wastes and the like; as germicides, insecticides, emulsifying agents, as, for example, for cosmetics, spray oils, water-repellent textile finishes, as lubricants, etc.

For convenience, what is said hereinafter will be divided into four parts:

Part 1 is concerned with the oxypropylation of castor oil;

Part 2 is concerned with the formation of the acidic ester from the oxypropylated castor oil described in Part 1, preceding;

Part 3 is concerned with the nature of the oxyproylated derivatives insofar that a cogeneric mixture is invariably obtained; and

Part 4 is concerned with certain valuable derivatives which can be obtained readily from the herein described fractional esters, as well as giving further data in regard to the use of the product in recovery of dry cleaner solvents.

PART 1 As has been pointed out previously the initial reaction involves castor oil (triricinolein) and propylene oxide. Broadly speaking, as has been stated previously, the oxypropylation of castor oil is well known and has been described in the patent literature; for instance, see U. S. Patent No. 2,233,382, dated February 25, 1941, and U. 3. Patent No. 2,281,419, dated April 28, 1942.

Also, as previously pointed out, I have found that instead of introducing approximately 13 moles of propylene oxide per ricinoleyl radical it is necessary to introduce at least fifty per cent more moles) to obtain a suitable raw material for subsequent esterification. Therefore, the actual procedure employed is the well known oxypropylation procedure with the proviso that it is carried out to a stage which, as has been previously stated, has not been recorded in the literature as far as I am aware.

Example In The particular autoclave used was one with a capacity of approximately 15 gallons or on the average of about 125 pounds of reaction mass. The speed of the stirrer could be varied from 150 to 350 R. P. M. The initial charge was pounds of castor oil and 1.05 pounds powdered caustic as catalyst. The reaction pot was flushed out with nitrogen, the autoclave sealed, and the automatic devices adjusted and set for injecting 90.2 pounds of propylene oxide in a 8-hour period. The pressure regulator was set for a maximum of 3537 pounds per square inch. However, in this partciular step and in all succeeding steps the pressure never got over about 32 pounds per square inch. In fact, this meant that the bulk of the reaction could take place and did take place at an appreciably lower pressure. The propylene oxide was added at a rate of about 1]. pounds per hour and at a comparatively moderate temperature, to wit, about 250- 255 F. (moderately higher than the boiling point of water). The initial introduction of propylene oxide did not start until the heating devices had raised the temperature to 245 F. At the completion of the reaction a sample as taken and oxypropylation proceeded as in Example 2a immediately following.

Example 2a 63 pounds of the reaction mass identified as Example 10, preceding, and equivalent to 17.5 pounds of castor oil, 45 pounds of propylene oxide, and .52 pound of catalyst were subjected to oxyalkylation with 27.02 pounds of propylene oxide.

The oxypropylation was conducted in substantially the same manner in regard to temperature and pressure as in Example la, preceding. Due to the smaller amount of propylene oxide introduced the time period was much shorter, to wit, 5 hours. The rate of oxide introduction was about 5 pounds per hour. At the end of the reaction period part of the sample was withdrawn and oxypropvlation continued as in Example 3a, immediately following.

Example 3a 85 pounds of the reaction mass identified as Example 2a, preceding, and equivalent to 16.52 pounds of castor oil, 68 pounds of propylene oxide, and .49 pound of catalyst, were permitted to stay in the autoclave. 6.39 pounds of propylene oxide were introduced in a 2-hour period. No additional catalyst was added.

The conditions of reaction as far as temperature and pressure were concerned were substantially the same as in Example 1a, preceding. The propylene oxide was added at the rate of about 3 pounds per hour. At the completion of the reaction part of the reaction mass was withdrawn and the remainder subjected to further oxypropylation as described in Example 4a, immediately following.

Example 4a 80.00 pounds of the reaction mass identified as Example 3a, preceding, and equivalent to 14.49 pounds of castor oil, 65.1 pounds of propylene oxide, and .43 pound of catalyst were permitted to stay in the autoclave. No additional catalyst was added.

The conditions in regard to temperature and pressure were substantially the same as in Example 1a, preceding. In this instance the oxide was addedin 4 hours. The amount of oxide added was 14 pounds. The addition was at the rate of about 3 pounds per hour.

Example 5a 80 pounds of reaction mass identified as Example 4a, preceding and equivalent to 10.72 pounds of castor oil, 67.35 pounds propylene oxide and .37 pound of catalyst, were left in the reaction vessel. To this reaction mass were added 11.92 pounds of propylene oxide at the rate of 4 pounds per hour. The reaction time was 3 /2 hours. Conditions were essentially the same as in the preceding examples.

Example 6a 80.00 pounds of the reaction mass identified as Example 5a, preceding, and equivalent to 10.72 pounds of castor oil, 69 pounds of propylene oxide, and .32 pound of catalyst, were permitted to stay in the autoclave. No additional catalyst was added.

The condition in regard to temperature and pressure were substantially the same as in Example 111, preceding. In this instance the oxide was added in 4 hours. The amount of oxide added was 10.4 pounds. The addition was at the rate of about 3 pounds per hour.

What has been said herein is presented in tabular form in Table 1 immediately following with some added information as to theoretical molecular weight, hydroxyl number, etc. Also, other examples have been presented in this table as it is not necessary to cite them all in detail as has been done with the preceding examples.

unsaturated monocarboxy acids having 18 carbonatoms. Reference to the acid in the hereto appended claims ob- I TABLE 1 Composition before Composition alter Theo. Max. Max Ex. No. in OH temp. pres Tlme' Castor Propy. Catalyst, Castor Prop. Catalyst Wt. value F i hrs.

oil, oxide, lb 011, oxide, lbs lbs. lbs. lbs. lbs.

35.00 1.05 35. 00 90.72 1. 05 3, 220 76 250-255 35-37 18 17. 50 45.00 t .52 17. '50 72.02 52 4, 610 65 250-255 35-37 5 16. 52 '68. 00 .49 16. 52 74. 39 49 4, 960 59 250-255 35-37 '2 14.49 65. .43 v 14.49 79.10 43 5,830 54 250-255 -37 4 12. 32 67. 35 .37 12. 32 79. 27 37 6, 700 52 250-255 35-37 3% 10. 72 69. 00 32 10. 72 79. 32 I .7, 57.0 60 250-255 35137 4 Attention is called to the fact that .Example 1a shown both in Table .1 andin the detailed examples preceding, is not intended to illustrate thisinvention. Examples 2a through 6a 'are, of course, intended to illustrate this invention. With regard to Example In, it will be shown later in .Part 4 that the amount of propylene oxide used in Example 1a is not satisfactory for the present invention.

The finalproduct, i. :e., at the end of the oxypropylation step, was a somewhat viscous, amber-colored fluid. In general the color ,gradually lightens as oxypropylation proceeds. The rproducts were water-insoluble at all stages, of course, but became xylene- :and even kerosene-soluble after a molecular weight of 20,000 or thereabouts had been reachedandgpassed. Thehydroxyl value mentioned in the above table immediately preceding were determined by the standard Verley-Bolsing method. This value is sometimes .referredto as acetyl value and is a well known determination in the art. it is to benoted that there is no compelteconversion ofpropylene oxide into the desired hydroxylatedbcompounds. This is indicated by the fact that theth'eoret'ical molecular weight based-on a statistical average is greater than the molecular weight when calculated on'the'basis of acetyl or hydroxyl value.

The fact that such pronounced variation takes place between hydroxyl molecular vweightand theoretical molecular weight, based on completeness of reaction, has been subjected-to examinationeand speculation, but no satisfactoryrationale has been suggested.

Actually, there is no completely satisfactory method for determinig'the molecular weights of these types of com- .pounds with a high degree of: accuracy. In some instances the acetyl value or hydroxyl valueserves as satisfactorily as an index to the molecular weight as any otherprocedure .due to the above limitations, and especially in the higher molecular weight range. If any 'difiiculty is encountered in the manufacture oftthe esters.as described ,in Part 2, preceding, .a stoichiometrical amount of :acid or acid compound should be taken which corresponds tothe indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a-matter of common knowledge and requires no 'furtherelaboration.

In the above tablethe time factors mentioned are gen- .erally longer than would ordinarily be required. Needless to say, the oxypropylation rate can be sped up by increasing'the agitation or the temperature and by a choice of suitable reaction vessels. However, asit is sometimes desirableto allow the reactionamass to stir for as long as a half-hour to one hour beforedrawinga sample after the addition'of propylene oxidelhas stopped, these time factors are-not considered excessive. I have chosen them at my own preference and they can be varied moderately one way or-the other, depending on ones inclination.

PART 2 As previously-pointed out,:the.presentlinvention iscon- 'cerned with a'cidic esters obtained from the oxypropylated derivativesldescribedin Part1, preceding, and polycarboxy acids, particularly tricarboxy acids like citric, and dicarboxy acids such as adipic acid; phthalic acid, or anhydride, 'succinic acid, diglycollic acid, sebaeic acid, azelaic acid, a'conitic acid, maleic acid, or anhydride, citraconic acid "or anhydride, maleic acid-or -anhydride adducts, as obtained by the Diels-Alder reaction from products such as "maleic anhydride, and cy'clopentadiene. Suchacids should be heat-stable sotheyare not decomposed during esterification. They rnay contain as many as 36 carbon atoms, as, ior ex-ample; the acids obtained by dimerization of unsaturatedl'fatt'y aoids, unsaturated nronocarboxy fatty'acids; or

stops.

viously includes the anhydrides orany other obvious equivalents. My preference, however, is to use polycarboxy acids having not over ,8 carbon atoms.

The production of .esters including acid esters (tractional esters) from polycarboxyacids and .glycols, .oI-other hydroxylated compounds, is well known. Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purposes of economy it is customary to use either the acid or the .zanhydride. A conventional procedure is employed. On .a laboratory scale one can employ a tresin pot of the kind described in -U.S. Patent No. 2,499,370, dated March 7, 1950, to De Groote and Keiser, and particularly with one more opening to permit the use of .a porous spreader if;hy.drochloric.acid gas is .used'as alcataalyst. Suchdeyice or absorption spreader consists of minute .alundum .thim- -blcs which are connected ;to a gas tube. One can add a sulfonic acid such as paratoluene :sultonic ;acid.as a catalyst. There is some objection to this because income vinstances there is some evidencethattthis .acid catalyst tends to decompose or rearrangelheataoxypropylated Compounds. it is particularly likely to do so if the esterification temperature is :too high. In the case of polycarboxy acids such as diglycollic ,acid which is strongly acidic there is no need to add anycatalyst. The use of .hydrochloriczacid zgas has-one advantage over paratoluenesulfonic .acid and thatis that atthe end of the reaction item be removed 'by flushing out with nitrogen, whereas there is ;no reasonably convenient means available of removing the paratoluene sultonic acid or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at an exceedingly slow rate so as to keep the reaction mass acidic. Only a trace of acid need be present. I have employed hydrochloric acid gas or the aqueous acid itself "to eliminate the initial basic material. My preference,'however, is to use no catalyst whatsoeverand to insure complete-dryness of the poly-pl as described in the final procedure just preceding Table 2.

The products obtained in Part 1, preceding, may considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered .and .refluxed with the xylene present .until the Water ,can be separated in a phase-separating trap. As soon ,as the product is substantially free from Water the distillation This preliminary step can be carried out in .the flask to beused'for esterification. If thereis any further deposition of sodium chloride during the reflux stage, needless to say, a second filtration may be required. In any event, the neutral or slightly acidic solutionof the oxypropylated derivatives described .in ,Part lis thendiluted further with sufficient Xylene, decalin, petroleum solvent, or the like, so that'one has obtained approximately a 45 %'65 solution. To this solution there is added a polycarboxylated reactant, as previously described, such as phthalic anhydride, succinic acid, oranhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete, as indicated by elimination of water or drop in carboxy value. Needlessto say, if one produces a half-ester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional andhave been so thoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual cata- Iyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end-product can then be acidified with just enough concentrated hydrochloric acid to just neutralize the residual basic catalyst. To this product one can then add a small amount of anhydrous sodium sulfate (sufficient in quantity to take up any Water that is present) and then subject the mass to centrifugal force so as to eliminate the hydrated sodium sulfate and probably the sodium chloride formed. The clear, somewhat viscous, straw-colored amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride, but in any event is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are not polyesters in the sense that there is a plurality of both poly-o1 racidals and acid radicals; the product is characterized by having only one poly-o1 radical.

In some instances and, in fact, in many instances, I have found that in spite of the dehydration methods employed above, a mere trace of water still comes through, and that this mere trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number of conventional procedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred to use the following procedure: I have employed about 200 grams of the poly-ol compounds, as described in Part 1, preceding; I have added about 60 grams of benzene and refluxed this mixture in the glass resin pot, using a phaseseparating trap, until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood of 130 C. to possibly 150 C. When all this water or moisture has been removed I also withdraw approximately grams, or a little less, benzene and then add the required amount of the carboxy reactant and also about 150 grams of a high-boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent efiect goes, act as if they were almost completely aromatic in character. Typical distillation data in the particular type I have employed and found very satisfactory is the following:

I. B. P., 142 C. ml., 242 C. 5 ml., 200 C. ml., 244 C. 10 ml., 209 C. ml., 248 C. 15 ml., 215 C. ml., 282 C. 20 ml., 216 C. ml., 252 C. 25 ml., 220 C. ml., 260 C. 30 ml., 225 C. ml., 264 C. 35 ml., 230 C. ml., 270 C. 40 ml., 234 C. ml., 280 C. 45 ml., 237 C. ml., 307 C.

After this material is added refluxing is continued and, of course, is at a high temperature, to wit, about to C. If the carboxy reactant is an anhydride, needless to say, no water of reaction appears; if the carboxy reactant is an acid, water of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated, I simply separate out another 10 to 20 cc. of benzene by means of the phaseseparating trap and thus raise the temperature to or C., or even to 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory, provided one does not attempt to remove the solvent subsequently, except by vacuum distillation, and provided there is no objection to a little residue. Actually, when these materials are used for a purpose, such as demulsification, the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin or an alkylated decalin which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

When starting with the castor oil product, as herein described, the raw material, I have found that xylene by itself is practically or almost as satisfactory as other solvents or mixtures. Decalin also is suitable. Actually,

TABLE 2 Amt.

Actual Polycarboxy reactant carboxy droxyl value TABLE 3 Amount solvent (are) Esterification time, hrs.

Solvent Xylene... 6

NOTE.I11 Tables 2 and 3, as mentioned in Table 1, Examples 1?) through 5b are not intended to illustrate this invention, but are only to serve as a comparison with the other examples. This comparison will be exemplified in Part 4.

The procedure for manufacturing the esters has been illustrated by preceding examples. If for any reason reaction does not take place in a manner that is acceptable, attention should be directed to the following de- (a) Recheck the hydroxyl or acetyl value of the oxypropylated material as in Part 1, preceding;

(b) If the reaction does not proceed with resonable speed, either raise the temperature indicated or else extend the period of time up to 12 or 16 hours if need be;

(c) If necessary, use /2 of paratoluene sulfonic acid, or some other acid, as a catalyst; and

(d) If the esterification doc-s not produce a clear product, a check should bemade to see if an inorganic salt such as sodium chloride or sodium sulfate is not precipitating out. Such salt should be eliminated, at least 31 exploration experimentation, and can be removed by tering.

Everything else being equal, as the size of the molecule increases and the reactive hydroxyl radical represents a smaller fraction of the entire molecule, more difiiculty is involved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperatures and long time of reaction, there are formed certain compounds whose compositions are still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been madeas to the nature of these compounds, such as being cyclic polymers of propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, i. e., of an aldehyde, ketone, or allyl alcohol. In some instances an attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant, for the reason that apparently under conditions of reaction less reactive hydroxyl radicals are present than indicated by the hydroxyl value. Under such circumstances there is simply a residue of the carboxylic reactant which can be removed by filtration, or, if desired, the esterification procedure can be repeated, using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value and conventional procedure leaves much to be desired, due either to the cogeneric materials previously referred to, or, for that matter, the presence of any inorganic salts or propylene oxide. Obviously this oxide should be eliminated.

The solvent employed, if any, can be removed from the finished ester by distillation, and particularly vacuum distillation. The final products or liquids are generally from almost black or reddish-black to dark amber in color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the iiikg, color is not a factor and decolorization is not justi- In the above instances I have permitted the solvents to remain present in the final reaction mass. In other instances I have followed the same procedure, using decalin or a mixture of decalin or benzene in the same manner and ultimately removed all the solvents by vacuum distillation.

PART 3 As previously mentioned, triricinolein may not only oxyalkylate on the secondary hydroxyl groups but also on the ester linkages. If one were concerned with a monohydroxylated material or a dihydroxylated material only, one might be able to write a formula which in essence would represent the particular product. However. in a more highly hydroxylated material the problem becomes increasingly more difiicult for reasons which have already been indicated in connection with oxypropylation.

It becomes obvious that when carboxylic acidic esters are prepared from such high molal molecular weight materials that the ultimate esterification product must, in turn, be a cogeneric mixture. Likewise, it is obvious that the contribution to the total molecular weight made by the polycarboxy reactant is small. Thus, one might expect that the effectiveness of the demulsifier in the form of the acidic fractional ester would be comparable to the esterified hydroxylated material. Remarkably enough, in practically every instance the product is distinctly better, and in the majority of instances much more effective.

PART 4 As pointed out previously the final product obtained is a fractional ester having free carboxyl radicals. Such product can be used as an intermediate for conversion into other derivatives which are effective for various purposes, such as the breaking of petroleum emulsions of the kind herein described. For instance, such product can be neutralized with an amine so as to increase its Water-solubility such as triethanolamine, tripropanolamine, oxyethylated triethanolamine, etc. Similarly, such product can be neutralized with some amine which tends to reduce the water-solubility such as cyclohexylamine, benzylamine, decylamine, tetradecylamine, octadecylamine, etc. Furthermore, the residual carboxyl radicals can be esterified with alcohols, such as low molal alcohols, methyl, ethyl, propyl, butyl, etc., and also high molal alcohols, such as octyl, decyl, cyclohexanol, benzyl alcohol, octadecyl alcohol, etc. Such products are also valuable for a variety of purposes due to their modified solubility. This is particularly true where surface-active materials are of value and especially in demulsification of water-in-oil emulsions.

Previous reference has been made to the fact that the herein described compounds are valuable in the recovery of dry cleaner solvent. These solvents are generally hydrocarbons such as gasoline, although sometimes chlorinated, and invariably contain certain additives such as dry cleaner soap, together with the extraneous material removed from soiled garments. Separation of suspended dirt and other matter from dry cleaner solvent is sometime something of a problem. Various mechanical devices including distillers, filters, etc., are employed. Electrical precipitation methods have been suggested. See, for example, U. S. Patents Nos. 2,573,966 and 2,573,967, both dated November 6, 1951, to Hamlin.

In a series of tests a gallon each of two diiferent samples of soiled dry cleaner solvent, principally Stoddard solvent, or the equivalent, were placed in S-liter bottles and tested with compounds lb, 61), 16b and 26b, at two different ratios, 1 to 3,000 in the first instance, and 1 to 5,500 in the second instance. The data are recorded in Table 4 and the note which follows:

TABLE 4 E N r h Timei X. 0. O OLIISY 01' Ex. No. compound Solvent Ratlo complete settling mom 113000 17 1:3000 11.5 1:3000 s 1:5500 115500 28 1:5500 13 mm 9 1 Still cloudy after 48 hours.

NorE.Ab0ve tests were made by shaking one-gallon samples of cleaning solvent with chemical, and allowing the samples to rest undisturbed. All samples were drawn from a large container, and agitated before sampling for 10 minutes. The solvent contained suspended par ticlcs, dirt, lint, etc., which attributed a very cloudy appearance to 1t.

Examination of the above data shows that the flocculating effect of the acidic esters begins somewhere beyond the point where castor oil has been treated with 40 moles of propylene oxide per mole of triricinolein as the initial reactant. These tests in a general Way are comparable to the demulsifying tests recorded in my co-pending application, Serial No. 281,647, filed AprillO, 1952.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a polycarboxy acid, and (B) excessively oxypropylated triricinolein with the proviso that (1) there be introduced at least 20 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical.

2. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a polycarboxy acid, and (B) excessively oxypropylated triricinolein with the proviso that (1) there be introduced at least 20 moles and not over 50 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical.

3. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained 1 1 that (1) there be introduced at least 20 moles and not over 40 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical.

4. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a polycarboxy acid, and (B) excessively oxypropylated triricinolein with the proviso that (1) there be introduced at least 20 moles and not over 40 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical; and with the further proviso that the triricinolein employed be in the form of commercial castor oil.

5. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a polycarboxy acid, and (B) excessively oxypropylated triricinolein with the proviso that 1) there be introduced at least 30 moles and not over 40 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical; and with the further proviso that the triricinolein employed be in the form of commercial castor oil.

6. Synthetic hydrophile products; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a dicarboxy acid, and (B) excessively oxypropylated triricinolein with the proviso that (1) there be introduced at least 30 moles and not over 40 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical; and

B with the further proviso that the triricinolein employed be in the form of commercial castor oil.

7. Synthetic hydrophile product; said synthetic hydrophile products being acidic fractional esters obtained by reaction between (A) a dicarboxy acid characterized by being free from any radical having more than 8 carbon atoms in any single group, and (B) excessively oxypropylated triricinolein with the proviso that (1) there be introduced at least 30 moles and not over 4-0 moles of propylene oxide per ricinoleyl radical, and that (2) there be employed at least one mole of the carboxy reactant for each reactive hydroxyl radical; and with the further proviso that the triricinolein employed be in the form of commercial castor oil.

8. The product of claim 7 wherein the dicarboxy acid is phthalic acid.

9. The product of claim 7 wherein the dicarboxy acid is maleic acid.

10. The product of claim 7 wherein the dicarboxy acid is succinic acid.

11. The product of claim 7 wherein the dicarboxy acid is citraconic acid.

12. The product of claim 7 wherein the dicarboxy acid is diglycolic acid.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,233,382 De Groote Feb. 25, 1941 2,343,432 Wells Mar. 7, 1944 2,576,285 De Groote Nov. 27, 1951 

1. SYNTHETIC HYDROPHILE PRODUCTS; SAID SYNTHETIC HYDROPHOLIC PRRODUCTS BEING ACIDIC FRACTIONAL ESTERS OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID, AND (B) EXCESSIVELY OXYPROPYLATED TRIRICINOLEIN WITH THE PROVISO THAT (1) THERE BE INTRODUCED AT LEAST ONE 20 MOLES OF PROPYL ENE OXIDE PER RICINOLEYL RADICAL, AND THAT (2) THERE BE EMPLOYED AT LEAST ONE MOLE OF THE CARBOXY REACTANT FOR EACH REACTIVE HYDROXYL RADICAL. 